Remote control systems

ABSTRACT

A mechanically actuated, radio frequency transmitter capable of providing radio frequency transmissions, without the need of stored electrical energy or external electrical energy, for utilization in remote control systems, consisting of an AC generator comprising a mechanically actuated rotor which is caused to rotate in close proximity to a stator assembly by rack and pinion means thereby resulting in induced electrical energy in the form of a sine wave; a tone generator; radio frequency oscillator means; and a single antenna for transmitting at least one signal generated by the radio frequency oscillator means. A receiver system eliminates the necessity for conventional oscillator by combining signals received from the transmitter, producing an intermediate frequency signal and demodulating the resulting signal by tone amplifier and filter means.

United States Patent [191 Kampmeyer 1 May 22, 1973 REMOTE CONTROL SYSTEMS Primary Examiner-Donald J. Yusko [75] Inventor: Roy Kampmeyer, Ambler, Pa. A"mey Thmas Femn et Assignee: Ambler Electronics, Ambler, Pa. Filed: July 13, 1971 Appl. No.: 162,094

[ ABSTRACT A mechanically actuated, radio frequency transmitter capable of providing radio frequency transmissions, without the need of stored electrical energy or external electrical energy, for utilization in remote control [.5 310/75 A, 2 0, systems, consisting of an AC generator comprising a 32 325/1 325/135 mechanically actuated rotor which is caused to rotate [51] Int. Cl. in lose proximity to a stator by rack and [58] Field of Search ..325/105, 185, 59, pinion means thereby resulting in induced electrical 343/225, 310/75 energy in the form of a sine wave; a tone generator; 322/38, 331/47, 71 radio frequency oscillator means; and a single antenna for transmitting at least one signal generated by the References Clted radio frequency oscillator means. A receiver system eliminates the necessity for conventional oscillator by UNITED STATES PATENTS combining signals received from the transmitter, 2,874,292 2/1959 Varley "325/185 X producing an intermediate frequency signal and 3, 967 Crump ..325/105 demodulating the resulting signal by tone amplifier 3,614,760 Zimmet X and filter means 3,633,106 1/1972 Willis ..325/l85 8 Claims, 4 Drawing Figures RF a H 5s 5s 58 6O If AMP Ll rIER DETECTOR Am m laa 5 A AMF ljFlER l a T l l 1 5 I 3212? Dim; are}? Basso,

l i r 1 l {73 72/ 7O 69 g? I f, w n. s v DELAY SWITCH i 65 1 G6 L v PATENTEU W I915 3,735.41 2

SHEET 1 OF 2 RF OSCILLATOR GENlSATOR l4 Fly. 1 I 0 TONE GENERATOR INVENTOR. Roy A. Kampmeyer Fi .3 BY Z ATTORNEY SHEET 2 BF 2 PATENTEB HAY 2 2 I973 I l I l I I I l I I1 l l I l I I I I I l I ll l l I l l I I 8 mm (l 19:26 llv Eda E mm E R M M @9850 56x6 $55 :3? llrlfi E Yawn. w wziucj v do 2 mm w .5530 II."I [II II I f I I III I I i I I I I I l I I I I .ll|.| mm n H E All mm 55E All: 5533 moBwGo A x3 A E52 wzop L H 8 8 wm 3 mm A I; ll. $1152, um A l INVENTOR. Roy A. Kampmeyer BY ATTORNEY.

band (88 1 REMOTE CONTROL SYSTEMS BACKGROUND OF THE INVENTION plications. Included are such private applications as garage door control systems, television control systems, light control systems, and the like. Industrial concerns have used remote control systems for regulation of equipment, a means of obtaining short range paging, and the like. In addition, various alarm systems, such as fire alarm systems and burglar alarm systems, are being used increasingly.

The common types of activation control systems are the following:

1. capacitance systems (including proximity systems) which depend on changes in capacity for activation,

2. photoelectric cell systems which depend on the interruption of a beam of radiation for activation,

3. ultrasonic control systems (employing ultrasonic sound waves) which depend on phase differences for activation,

4. trip wire systems which depend simply on movement of a wire for activation,

5. microswitch activated systems which depend on movement of a switch for activation, and

6. RF transmission systems, which are often combined with one or more of the aforementioned control systems for transmission of a signal to a remote radio receiver when actuated.

Typically, such control systems depend on stored electrical energy (i.e., batteries) or an external electrical power source (i.e., a conventional 115 volt, 60 cycle power source). The use of batteries necessitates the periodic testing of the batteries and their periodic replacement, as the batters cells deteriorate. When the system is dependent upon a 115 volt, 6O cycle power source the electrical hookup becomes cumbersome (especially when the power source must be wired to all components, including remote components) and, in the event of a power failure, the system becomes entirely inoperative.

One radio frequency transmission scheme is that set forth in US. Pat. No. 3,544,987, which employs a centrally located radio receiver to detect a signal from one or more remote transmitters. In the system disclosed by the patent, a magnet is affixed to a movable element such as a door or a window and used to operate a two position reed switch on a sensing device. Each sensing device includes a radio frequency oscillator, a PM modulator operating in the FM broadcasting frequency 108 mo.) and high audio frequency oscillators for supplying tone signals to modulate the radio frequency carrier signal. Power for the oscillators is supplied from a capacitor which is maintained fully charged by a battery. When the reed switch disconnects the capacitor from the battery and couples the capacitor to the tone and radio'frequency oscillator circuits, the latter generates a burst of RF signal frequency modulated with audio tone signals. This frequency modulated signal is then radiated as an electromagnetic wave by an antenna to the centrally located radio receiver. In addition to its dependency on batteries as a power source, the sensing device of the transmitter requires the additional installation of a magnet to activate the two position reed switch.

In order to overcome the problems associated with battery operated systems and wired systems, considerable efiort has been made to develop a remote control system in which the detector could be used to generate an electrical signal in response to mechanical activation without any other power source. Not only would such a system have advantages already mentioned, but such a system would also have the advantage that it could be expanded by multiplying the number of remote detectors without altering the electrical or mechanical requirements of the system.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved, mechanically actuated, radio frequency transmitter.

Another object of the present invention is to provide a self-powered, mechanically actuated, radio frequency transmitter consisting of an AC generator, a tone generator, a radio frequency oscillator and an antenna.

A further object of the present invention is to provide radio frequency transmissions for remote control systems without the need of a battery or other external electrical power.

Still another object of the present invention is to provide a new and improved remote control radio frequency transmission system which is modular in design and easily expandable for incorporation of additional transmitter units.

Yet another object of the present invention is to provide a remote control radio frequency transmission system containing new and improved means for simultaneously generating and receiving two different radio frequency signals.

In accordance with the present invention, a mechanically actuated, radio frequency transmitter is provided which is capable of producing radio frequency transmissions without the need of stored electrical energy or external electrical energy. The transmitter consists of an AC generator, atone generator, a radio frequency oscillator, and an antenna. The AC generator comprises a mechanically actuated rotor which rotates in close proximity to a stator assembly to produce the required electrical energy for generation of a signal and the transmission of that signal from the transmitter antenna.

In accordance with one embodiment of the-present invention two different radio frequency signals are simultaneously generated and-received by the remote control radio frequency transmission system.

BRIEF DESCRIPTION OF THE DRAWINGS Other and further objects, advantages and features of the invention will be apparent to those skilled in the art from the following detailed description thereof, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a highly schematic block drawing of a remote control transmitter in accordance with the pres ent invention;

FIG. 2 is a highly schematic drawing of an AC generator in accordance with one embodiment of the present invention;

FIG. 3 is a highly schematic drawing of an AC generator in accordance with another embodiment of the present invention; and

FIG. 4 is a highly schematic block drawing of receiver and activating circuitry which can be employed in accordance with one embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the representative embodiment of the present invention shown in FIG. 1 a remote control transmitter is provided which includes a sensor device composed of an AC generator 12, a tone generator 13, a radio frequency oscillator 14 and an antenna 16. The overall size of sensor device 10 is small enough to be inconspicuously mounted in a desired location or carried by an individual.

A preferred embodiment of the AC generator 12 is illustrated in FIG. 2. The illustrated embodiment employs a rack and pinion arrangement in which rack is in engagement with pinion 21. When extension 22 of rack 20, which is held in place by support member 23, is pushed, spring 24, which is coupled to pinion 21, is wound a few turns. By continuing to push on extension 22, rack 20 becomes disengaged from pinion 21 and spring 24 is released causing rotor 26, which is attached to pinion shaft 27, to spin rapidly. Rotor 26, a multipole permanent magnet, is located in close proximity to stator assembly 28. Winding on stator assembly 28 picks up the field alterations of rotor 26 resulting in induced electrical energy in the form of a sine wave which is transmitted to tone generator 13 and radio frequency oscillator 14 (see FIG. 1) via lines 32.

If desired, a spring (not shown) can be employed to assist the return of rack 20 into engagement with pinion 21 when the force pushing extension 22 is released.

FIG. 3 illustrates an alternative embodiment for engaging and disengaging a spring which turns a rotor to produce the electrical energy supplied to tone generator 13 and radio frequency oscillator 14 of FIG. 1. Referring to FIG. 3, magnets 36 and 37 are attached to the pinion plate 38 and the rotor plate 39, respectively, such that at rest the magnets attract. Helical springs 40 and 41 are attached to pinion plate 38 and rotor plate 39, respectively, such that when magnets 36 and 37 are at rest springs 40 and 41 are at rest with no internal force on the system.

When rack 20 is moved, rotor plate 39 is turned by pinion plate 38 due to the attraction between magnets 36 and 37. When the internal force of rotor plate spring 41 exceeds the force of the attracting magnets 36 and 37, said magnets pull apart and rotor plate 39 reverses directions through a period of damped oscillations turning rotor 26 until the rest position for magnet 37 is once again reached. Simultaneously, spring 40 acts to return magnet 36 to its rest position and rack 20 to its initial position.

Instead of employing linear motion for activating the system rotary motion can be employed. For example, a trip lever could be arranged to rotate around a pivot thereby causing a spring to become wound around the pivot position and be released at a predetermined position.

Referring once again to FIG. 1, when a signal is generated by AC generator 12, producing a series of sine waves which are passed to tone generator 13 and radio frequency oscillator 14, generator 13 and oscillator 14 are powered during the positive excursions by AC generator 12. Tone generator 13 is simply a high audio frequency oscillator for supplying tone signals to modulate the radio frequency carrier signal generated by radio frequency oscillator 14. Thus, tone generator 13 can be a simple Hartley oscillator. The radio frequency oscillator 14 is any oscillator, such as a tunnel type diode oscillator, which is capable of producing a radio frequency signal suitable for short range transmission on the VHF wavelengths. Preferably, oscillator 14 is capable of oscillating on more than one frequency simultaneously and is frequency or amplitude modulated. Antenna 16 is used to transmit the signals which are generated to a suitable radio receiver which is tuned to the same radio frequencies transmitted from sensor device 10.

Combined receiver and activating circuitry suitable for use in the present invention are illustrated inFlG. 4, in which the activating circuitry is enclosed inside a dotted line. It will be understood that these circuits are supplied with DC power from a suitable power supply source which is not shown. In a preferred embodiment, a rechargable battery is employed in combination with a l 15 volt AC power source; the battery being continuously recharged by the AC power source. The rationale behind the use of a battery and the continual charging of the battery is that the receiver will continue to operate even if the AC plug is removed from conventional electric circuits or even if there is a general power failure.

The signal (a dual frequency signal) received by antenna of the receiver is transmitted to two radio frequency amplifiers 52 and 53. Each of the two frequencies produced by sensor device 10 (FIG. 1) in accordance with the preferred practice of the present invention are selectively amplified by these radio frequency amplifiers and are gain controlled in accordance with conditions established by the control or activating circuitry inside the dotted line. The two amplified frequencies are combined in mixer 55 and a conventional IF amplifier is employed to amplify the resulting signal. The signal is then transmitted in turn to a detector 58 and a tone amplifier 60. Tone amplifier 60 amplifies the tone modulation obtained by detector 58. Filter 62 insures that the only signal proceeding through the system is a proper tone frequency, thereby excluding other unwanted frequencies.

The described RF-IF audio section of the receiver represents a novel approach to receiver design even though conventional equipment can be employed. According to the present invention the signals which are received by antenna 50 are made to beat with each other to produce the IF signal thereby eliminating the necessity for the usual oscillator of receiver systems. This provides improved frequency stability of the IF signal.

The control circuitry shown in the dotted line of FIG. 4 operates on the signal transmitted from the RF-IF audio section of the receiver. Switch 65 has on and off positions. In its off position, gain control voltage transmitted to radio frequency amplifiers 52 and 53 is zero so that these radio frequency amplifiers can be shut off preventing passage of any signal through the receiver.

The system is enabled by turning switch 65 to an on position. By employing delay 66 positive gain control voltage to the radio frequency amplifiers of the audiosection of the receiver can be delayed. Such a delay circuit is advantageous when the receiver is employed, for example, as an intrusion alarm system. The delay stage permits a person to activate or enable the system and leave a protected premise without setting off the alarm. After a short delay period, the system becomes activated and any transmitted tone is detected by the peak detector 67 which is latched on by latching circuit 69 which is controlled by switch 65. Delay circuit 70, like delay circuit 66 is useful in connection with intrusion alarm systems, and is employed as an entry delay circuit to permit a person to enter an area and turn switch 65 to an off position, thus preventing activation of the alarm.

If the system is not deactivated, relay driver 72 is activated which in turn activates output relay 73 shorting output terminals 75. The system remains in this state until the alarm control switch 65 is turned off.

By locating the receiver of the remote control system in one central location, several remote transmitters or sensor devices operating on the same wave length and antenna polarization can be used to activate the receiver. A single switch control 65 regulates the entire system.

Output terminals 75 can be used to activate an alarm system, control mechanical equipment such as a garage door opener, etc. Output terminals 75 may also be suitably hooked to loudspeaker system for generating an audible sound which would alert an individual that the system had then activated. It will be understood for certain of these applications the delay circuits, such as delay circuits 66 and 70, would not serve any useful purpose and could be deleted entirely.

From the foregoing, it will be seen that this invention is well adapted to obtain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the system. The system is compact, easy to install, provides completely wireless installation of transmitters, and offers many other advantages. Unlike conventional transmitters, the transmitter of the present invention has a self generating power source and does not require batteries or external hookup to a power source. The transmitter also has fewer components than typical transmitters, providing a simplicity which improves the reliability of the transmitter and lowers the overall equipment costs. The transmitter is self contained and does not require a magnet to be separately mounted for operation. By transmitting continuous dual radio frequencies simultaneously to properly activate the control system in accordance with a preferred embodiment of the present invention the possibility of single frequency interference which would cause a false signal is thereby eliminated. A simplified superhetrodyne receiver is disclosed which does not require an oscillator for down conversion of the received signal to a suitable IF frequency. The elimination of the conventional oscillator has the advantage of removing any possible drift element in the system and simplifies initial tuning procedures.

The remote control system of the present invention is applicable to a wide variety of private and industrial applications which require a remote controlled annunciator system, equipment regulation system, and the like.

Obviously, many other modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof.

What is claimed is:

1. A mechanically-actuated radio transmitter which produces radio frequency transmissions by a self generated power source, said transmitter consisting essentially of:

radio frequency oscillator means for providing at least one radio frequency carrier signal;

a tone generator for modulating the radio frequency carrier signal generated by the radio frequency oscillator means;

a single antenna for radiating as an electromagnetic wave the radio frequency carrier signal generated by the radio frequency oscillator means and modulated by the tone generator; and

an AC generator for supplying alternating current to the radio frequency oscillator means and the tone generator, said AC generator including means for converting mechanical energy intoalternating current including rack and pinion means for rotating a rotor in close proximity to a stator assembly thereby inducing an alternating current in an electric coil surrounding the stator assembly.

2. A mechanically-actuated radio transmitter as claimed in claim 1 wherein the AC generator contains spring means for returning the rack and pinion to its original position after converting mechanical energy into an alternating current.

3. A mechanically-actuated radio transmitter as claimed in claim 1 wherein the radio frequency oscillator means provides two different radio frequency carrier signals simultaneously which are each modulated by the tone generator and are radiated as electromagnetic waves by the single antenna.

4. A mechanically-actuated radio transmitter which produces radio frequency transmissions by a selfgenerated power source, said transmitter comprising:

radio frequency oscillator means for providing two different radio frequency carrier signals simultaneously;

a tone generator for modulating the two radio frequency carrier signals generated by the radio frequency oscillator means;

a single antenna for radiating as electromagnetic waves the radio frequency carrier signals which have been generated by the radio frequency oscillator means and modulated by the tone generator; and

an AC generator for supplying alternating current to the radio frequency oscillator means and the tone generator, said AC generator including rack and pinion means for converting mechanical energy into said alternating current by rotating a rotor in close proximity to a stator assembly thereby inducing a voltage in an electric coil surrounding the stator andhaving spring means for automatically returning the rack and pinion means to its original position.

5. A remote controlled radio frequency transmission system, comprising:

at least one mechanically-actuated radio transmitter which produces radio frequency transmissions by a self-generated power source and includes radio frequency oscillator means for providing at least one radio frequency carrier signal;

a tone generator for modulating the radio frequency carrier signal generated by the radio frequency oscillator means;

a single antenna for radiating as an electromagnetic wave the radio frequency carrier signal generated by the radio frequency oscillator means and modulated by the tone generator;

an AC generator for supplying alternating current to the radio frequency oscillator means and the tone 7. A remote controlled radio frequency transmission system as defined in claim 5 wherein the radio frequency oscillator means provides two different radio frequency carrier signals simultaneously which are each modulated by the tone generator and are radiated as electromagnetic waves by the single antenna of the transmitter and wherein the receiver comprises two radio frequency amplifiers and a single antenna for receiving the two different radio frequency carrier signals radiated from the single antenna of said transmitter, and wherein the amplified frequencies from each of the radio frequency amplifiers of the receiver are combined to produce an intermediate frequency signal which is demodulated and then acted upon by the receiver.

8. A remote controlled radio frequency transmission system as defined in claim 7 wherein the intermediate frequency signal is demodulated by tone amplifier and filter means. 

1. A mechanically-actuated radio transmitter which produces radio frequency transmissions by a self generated power source, said transmitter consisting essentially of: radio frequency oscillator means for providing at least one radio frequency carrier signal; a tone generator for modulating the radio frequency carrier signal generated by the radio frequency oscillator means; a single antenna for radiating as an electromagnetic wave the radio frequency carrier signal generated by the radio frequency oscillator means and modulated by the tone generator; and an AC generator for supplying alternating current to the radio frequency oscillator means and the tone generator, said AC generator including means for converting mechanical energy into alternating current including rack and pinion means for rotating a rotor in close proximity to a stator assembly thereby inducing an alternating current in an electric coil surrounding the stator assembly.
 2. A mechanically-actuated radio transmitter as claimed in claim 1 wherein the AC generator contains spring means for returning the rack and pinion to its original position after converting mechanical energy into an alternating current.
 3. A mechanically-actuated radio transmitter as claimed in claim 1 wherein the radio frequency oscillator means provides two different radio frequency carrier signals simultaneously which are each modulated by the tone generator and are radiated as electromagnetic waves by the single antenna.
 4. A mechanically-actuated radio transmitter which produces radio frequency transmissions by a self-generated power source, said transmitter comprising: radio frequency oscillator means for providing two different radio frequency carrier signals simultaneously; a tone generator for modulating the two radio frequency carrier signals generated by the radio frequency oscillator means; a single antenna for radiating as electromagnetic waves the radio frequency carrier signals which have been generated by the radio frequency oscillator means and modulated by the tone generator; and an AC generator for supplying alternating current to the radio frequency oscillator means and the tone generator, said AC generator including rack and pinion means for converting mechanical energy into said alternating current by rotating a rotor in close proximity to a stator assembly thereby inducing a voltage in an electric coil surrounding the stator and having spring means for automatically returning the rack and pinion means to its original position.
 5. A remote controlled radio frequency transmission system, comprising: at least one mechanically-actuated radio transmitter which produces radio frequency transmissions by a self-generated power source and includes radio frequency oscillator means for providing at least one radio frequency carrier signal; a tone generator for modulating the radio frequency carrier signal generated by the radio frequency oscillator means; a single antenna for radiating as an electromagnetic wave the radio frequency carrier signal generated by the radio frequency oscillator means and modulated by the tone generator; an AC generator for supplying alternating current to the radio frequency oscillator means and the tone generator, said AC generator including rack and pinion means for converting mechanical energy into alternating current; and a receiver for receiving the radio frequency carrier signal radiated from the single antenna of the transmitter.
 6. A remote controlled radio frequency transmission system as defined in claim 5 wherein the AC generator has spring means for returning the rack and pinion means to its original position.
 7. A remote controlled radio frequency transmission system as defined in claim 5 wherein the radio frequency oscillator means provides two different radio frequency carrier signals simultaneously which are each modulated by the tone generator and are radiated as electromagnetic waves by the single antenna of the transmitter and wherein the receiver comprises two radio frequency amplifiers and a single antenna for receiving the two different radio frequency carrier signals radiated from the single antenna of said transmitter, and wherein the amplified frequencies from each of the radio frequency amplifiers of the receiver are combined to produce an intermediate frequency signal which is demodulated and then acted upon by the receiver.
 8. A remote controlled radio frequency transmission system as defined in claim 7 wherein the intermediate frequency signal is demodulated by tone amplifier and filter means. 